超快泵探针对GaAs中X射线诱导的瞬态光学反射率变化的探测（英文）  

Ultrafast pump-probe detection of X-ray induced transient optical reflectivity changes in GaAs

作　　者：王博[1,2,3] 白永林[1,2] 徐鹏[2] 缑永胜[2,3] 朱炳利[2] 白晓红[1] 刘百玉[2] 秦军君 

机构地区：[1]中国科学院西安光学精密机械研究所,瞬态光学与光子技术国家重点实验室,陕西西安710119 [2]中国科学院西安光学精密机械研究所,超快诊断技术重点实验室,陕西西安710119 [3]中国科学院大学,北京100049

出　　处：《红外与激光工程》2015年第10期3130-3133,共4页Infrared and Laser Engineering

基　　金：国家自然科学基金(11305259)

摘　　要：理论估算并实验验证了在X射线脉冲激发下低温砷化镓的光学折射率调制特性。泵浦-探针实验表明,低温砷化镓中存在的高密度复合缺陷大大减小了载流子寿命,使超热电子的弛豫时间小于1×10-12s,载流子的复合时间小于2×10-12s,折射率的扰动时间约为2×10-12s。通过理论分析,给出了自由载流子和俄歇效应对该弛豫过程的定量估算,与实验结果吻合较好。该研究表明低温生长砷化镓是一种有效的可用于单次瞬态皮秒时间分辨X射线探测的材料。The optical index modulation was theoretically estimated and demonstrated under short X-ray excitation in low-temperature-grown GaAs （LT_GaAs）. Hot-electron thermalization time 〈1 ps, carrier recombination time 〈2 ps and the duration of the index perturbation was determined by the carrier recombination time which was of order -2 ps in LT_GaAs with a high density of recombination defects. Predictions of radiation-induced changed in the optical refractive index were in reasonably good agreement with the limited experimental data available, suggesting that LT_GaAs was a highly promising material for high speed single transient ionizing radiation detector.

关 键 词：低温生长砷化镓 X射线探测器 折射率扰动 皮秒时间分辨 

分 类 号：TN29[电子电信—物理电子学]